This section provides background information related to the present disclosure, which is not necessarily prior art.
In an exhaust gas distribution system, exhaust gas from one cylinder provides exhaust gas recirculation to an entire engine. A three-way valve downstream of the dedicated cylinder is used to direct exhaust flow either to an emissions control catalyst, or back to an intake of the system (known as an exhaust gas distribution loop). This valve is subject to high-temperature gasses flowing directly from the exhaust port(s) of the dedicated cylinder. In addition, when the dedicated cylinder is run rich, the exhaust products from the rich combustion cycle may harm or cause premature wear to the catalyst. Because of this, a zero or low leakage valve is desired to direct all dedicated cylinder exhaust back to the intake and prevent flow to the catalyst. A low leakage valve also helps maintain the desired EGR rate. While current valves are suitable for their intended use, they are subject to improvement. For example, current valves typically have low temperature limitations, and have difficulties meeting the low leakage requirements, especially over time. A three-way exhaust gas distribution valve that can perform well in a high-temperature environment and exhibits little or no exhaust leakage would therefore be desirable. The present disclosure advantageously provides for such an exhaust gas distribution valve, as explained in detail herein and as one skilled in the art will appreciate.